// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_WM_PUBLIC_DRAG_DROP_CLIENT_H_
#define UI_WM_PUBLIC_DRAG_DROP_CLIENT_H_

#include "ui/aura/aura_export.h"
#include "ui/base/dragdrop/drag_drop_types.h"
#include "ui/gfx/native_widget_types.h"

namespace gfx {
class Point;
}

namespace ui {
class LocatedEvent;
class OSExchangeData;
}

namespace aura {
class Window;
namespace client {

    // An interface implemented by an object that controls a drag and drop session.
    class AURA_EXPORT DragDropClient {
    public:
        virtual ~DragDropClient() { }

        // Initiates a drag and drop session. Returns the drag operation that was
        // applied at the end of the drag drop session. |screen_location| is in
        // screen coordinates.
        virtual int StartDragAndDrop(const ui::OSExchangeData& data,
            aura::Window* root_window,
            aura::Window* source_window,
            const gfx::Point& screen_location,
            int operation,
            ui::DragDropTypes::DragEventSource source)
            = 0;

        // Called when mouse is dragged during a drag and drop.
        virtual void DragUpdate(aura::Window* target,
            const ui::LocatedEvent& event)
            = 0;

        // Called when mouse is released during a drag and drop.
        virtual void Drop(aura::Window* target,
            const ui::LocatedEvent& event)
            = 0;

        // Called when a drag and drop session is cancelled.
        virtual void DragCancel() = 0;

        // Returns true if a drag and drop session is in progress.
        virtual bool IsDragDropInProgress() = 0;
    };

    AURA_EXPORT void SetDragDropClient(Window* root_window,
        DragDropClient* client);
    AURA_EXPORT DragDropClient* GetDragDropClient(Window* root_window);

} // namespace client
} // namespace aura

#endif // UI_WM_PUBLIC_DRAG_DROP_CLIENT_H_
